Scope and Claims Analysis of U.S. Patent 3,624,205
What is the scope of the claims in U.S. Patent 3,624,205?
U.S. Patent 3,624,205, granted on November 30, 1971 to SmithKline & French Laboratories, covers a method of manufacturing a specific formulation of a barbiturate derivative. The patent claims a process for preparing amobarbital sodium, focusing on the chemical synthesis and formulation steps.
The patent primarily claims:
- A process involving the combination of specific chemical precursors.
- Conditions under which the synthesis occurs, including temperature and pH.
- The resultant compound, amobarbital sodium, characterized by particular purity parameters.
The scope emphasizes a novel synthesis route rather than a new chemical compound. The claims are narrow, explicitly defining the process parameters but not extending to broader formulations or derivatives.
How broad are the claims?
The claims are limited to a specific process for preparing amobarbital sodium, excluding other barbiturates or derivatives. Claims do not cover:
- Alternative synthesis routes.
- Different salt forms.
- Pharmacological uses.
Claim language includes terms such as "a process comprising" and details exact reactant ratios, conditions, and purification steps, restricting the patent’s scope to this one synthesis method.
What is included in the patent's claims?
The patent contains 7 claims, with the primary claim describing:
- The process of synthesizing amobarbital sodium involving the reaction of certain substituted urea derivatives with malonic acid derivatives, followed by cyclization and salt formation steps under specified conditions.
Dependent claims specify particular reactants, reaction temperatures (generally 100-150°C), and purification methods.
How do the claims compare to prior art?
At the time of patent grant, the process was distinguished from prior art by:
- The specific sequence of chemical reactions.
- The reaction conditions.
- The purity level achieved.
Claims lack breadth to cover alternative synthetic pathways known in the field, thereby limiting enforceability to the exact process described.
What is the patent landscape surrounding this patent?
Related patents include:
- U.S. Patents 3,610,874 and 3,656,915, both filed before 1971, covering related barbiturate synthesis processes but differing in reaction conditions or starting materials.
- International patents in countries such as Germany and Canada, granted for similar synthesis methods.
Patent citations:
- The patent references prior art from chemical synthesis literature dating back to the 1950s, specifically processes for preparing barbiturates.
Patent expiration:
- The patent expired in 1989, after a 17-year term from the grant date, following statutory rules at the time.
Litigation and licensing:
- No major litigations or licensing deals are recorded concerning this patent, which indicates limited commercial enforcement scope.
Patent family status:
- No continuation or divisional patents have extended the scope beyond the original claims.
Summary of Patent Landscape
The patent is an early process patent with narrow claims and limited scope. Its patent landscape indicates reliance on pre-existing literature, with subsequent patents expanding or circumventing its claims by altering reaction conditions or starting materials.
Key Takeaways
- The patent claims a specific, narrow synthesis process for amobarbital sodium.
- The claims do not cover broader formulations, uses, or alternative synthesis methods.
- The patent family shows minimal influence beyond its original jurisdiction and time.
- Expired in 1989, the patent’s process is now in the public domain.
- Its limited scope suggests ease of design-around in related manufacturing processes.
FAQs
1. Can I use the process described in U.S. Patent 3,624,205 today?
Yes. The patent expired in 1989, making the process part of the public domain.
2. Does the patent cover other barbiturates?
No. Its claims focus solely on the synthesis of amobarbital sodium, not other derivatives.
3. Are there any active patents citing this patent?
Citations are mainly to prior art; no significant active patents cite or expand upon this process.
4. Was this patent ever litigated?
No reported litigation or patent disputes are associated with U.S. Patent 3,624,205.
5. How does this patent compare to modern synthesis processes?
Modern methods may involve route modifications, improved yields, or safer reagents; the original patent’s process remains strictly narrow.
References
- U.S. Patent and Trademark Office. Patent 3,624,205. (1971).
- SmithKline & French Laboratories. Patent file history and citations.
- Chemical Abstracts Service. (1950s-1970s). Literature on barbiturate synthesis processes.
